Traumatic hyphema: causes, symptoms, diagnosis, treatment

Hyphema - the presence of blood in the anterior chamber. The amount of blood may be microscopic (microhyphema), when erythrocytes in the aqueous humor are visible only with biomicroscopy, or the blood is located in a layer in the anterior chamber.

In total hyphema, blood fills the entire anterior chamber. Total hyphema with coagulated blood turns black, it is called eight-point. Traumatic hyphema is associated with blunt or penetrating injury to the eye. Most hyphemas gradually resolve on their own without any consequences, but repeated bleeding, increased intraocular pressure and staining of the cornea with blood may occur.

Epidemiology of traumatic hyphema

Traumatic hyphema occurs with blunt or penetrating trauma. Traumatic hyphema is common in young, active men, with a male-to-female ratio of approximately three to one. The risk of complications, such as recurrent bleeding, uncontrolled increase in intraocular pressure, or blood staining of the cornea, increases with increasing hyphema size. An exception is patients with sickle cell hemoglobinopathies. Such patients are at increased risk of complications regardless of the size of the hyphema.

Up to 35% of patients suffer from recurrent bleeding. In most cases, recurrent bleeding develops within 2-5 days after injury, is usually more massive than the previous hyphema, with a greater tendency to develop complications.

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Pathophysiology of traumatic hyphema

Compression forces from blunt trauma rupture the iris and ciliary body vessels. Ciliary body ruptures damage the large arterial circle of the iris. Penetrating wounds directly damage blood vessels. Clots of clotted blood plug the damaged vessels. Repeated bleeding occurs with retraction and lysis of these clots. Intraocular pressure increases sharply with block of the trabecular meshwork by red blood cells, inflammatory cells, and other organic substances. Intraocular pressure also increases with pupillary block, a blood clot in the anterior chamber, or mechanical block of the trabecular meshwork. This form of pupillary block often occurs with eight-point hyphema - total clotted hyphema that impede the circulation of intraocular fluid. Impaired circulation of aqueous humor leads to a decrease in the oxygen concentration in the anterior chamber and blackening of the clot.

In patients with sickle cell disease and other conditions, when sickle cells form, red blood cells become rigid and easily lodged in the trabecular meshwork, increasing intraocular pressure even with small hyphema. In microvascular disorders, patients may experience vascular occlusion and damage to the optic disc with low intraocular pressure.

Symptoms of traumatic hyphema

Patients have a history of trauma. Careful questioning about the time and mechanism of injury is essential to assess the likelihood of additional damage and the need for in-depth examination and treatment. Patients may be asymptomatic, with decreased visual acuity, photophobia, and pain. Increased intraocular pressure is sometimes accompanied by nausea and vomiting. There may be signs of orbital trauma or damage to other ocular tissues.

Diagnosis of traumatic hyphema

Biomicroscopy

Slit lamp examination reveals red blood cells circulating in the anterior chamber, sometimes hyphema. There may be signs of trauma in other structures of the eye, such as cataracts, phacodenes, subconjunctival hemorrhage, foreign bodies, wounds, iris sphincter ruptures, or ruptures in the area of the iris root (iridodialysis).

Gonioscopy

Gonioscopy should be performed after the risk of rebleeding has disappeared. After a period of time, 3 to 4 weeks after the injury, the angle may be found to be intact or, more commonly, angle recession may be detected. Cyclodialysis may develop.

Posterior pole

At the posterior pole, evidence of blunt or penetrating trauma may be seen. Retinal contusion, choroidal tears, retinal detachments, intraocular foreign bodies, or vitreous hemorrhage may be present. Scleral indentation examination should be delayed until the risk of rebleeding has passed.

Special tests

An ultrasound B-scan should be performed on every patient when the posterior pole cannot be examined. If orbital fractures or an intraocular foreign body are detected during the clinical examination, the patient is referred for orbital CT scanning.

Every black or Hispanic patient, as well as patients with a complicating family history, should have a blood test or hemoglobin electrophoresis to determine whether they have sickle cell disease.

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Treatment of traumatic hyphema

The affected eye is covered with a bandage, the patient is placed on the bed with the head elevated. It is necessary to avoid taking acetylsalicylic acid, nonsteroidal anti-inflammatory drugs; local cycloplegic agents and glucocorticoids are used. To prevent rebleeding, the patient takes (orally) aminocaproic acid and antifibrinolytics. Aminocaproic acid can cause postural hypotension, nausea and vomiting, so it should be avoided during pregnancy and in patients with cardiac, hepatological or renal diseases. In case of increased intraocular pressure, beta-blockers, a-adrenergic agonists or carbonic anhydrase inhibitors are prescribed locally. Miotics can cause inflammation - they should not be prescribed. In addition, carbonic anhydrase inhibitors are administered orally or intravenously, with the exception of patients with sickle cell hemoglobinopathies, since they increase the pH of the intraocular fluid, increasing the formation of the sickle form of hemoglobin. Such patients should be very cautious when prescribing hyperosmotic agents, since an increase in blood viscosity leads to an increase in the concentration of the pathological form of hemoglobin.

Patients with extensive non-resolving hyphema and early corneal imbibition with blood, as well as in cases with uncontrolled intraocular pressure, are recommended to undergo surgery. The timing of surgery to control intraocular pressure is individual and depends on the patient. Surgery is necessary for patients with a normal optic disc with an intraocular pressure of 50 mm Hg for 5 days or more than 35 mm Hg for 7 days. Patients with an altered optic disc, corneal endothelial pathology, sickle cell hemoglobinopathy or its signs require earlier surgery. In addition, surgery is indicated for patients with sickle cell anemia with an intraocular pressure of more than 24 mm Hg and a duration of more than 24 hours.

Surgical procedures to remove hyphema include lavage of the anterior chamber, squeezing the blood clot through an incision in the limbus, or removing it with anterior vitrectomy instruments. To prevent rebleeding, clot removal is performed within 4 to 7 days after the injury. In most cases, a gentle filtering operation is usually performed to control intraocular pressure.